大洋锰结核与药渣共浸出氧化还原过程研究

来源期刊:中南大学学报(自然科学版)2018年第10期

论文作者:冯雅丽 仇云飞 李浩然 杜竹玮 康金星 王昌

文章页码:2373 - 2381

关键词:药渣;大洋锰结核;动力学分析;塔菲尔曲线

Key words:pharmaceutical residue; oceanic manganese nodules; kinetic study; Tafel curve

摘    要:以药渣为大洋锰结核还原剂,研究药渣湿法还原锰结核浸出特性。考察搅拌速率、液固比、硫酸浓度、药渣用量和反应温度对锰浸出的影响,利用稳态极化曲线测定浸出反应动力学参数。研究结果表明:在搅拌速率为400 r/min、液固比为10:1、硫酸浓度为0.94 mol/L、药渣用量为5 g、浸出温度为363 K的条件下浸出300 min,锰浸出率达95.78%。在343~368 K间,浸出过程受化学反应控制,表观活化能为40.74 kJ/mol。在酸性环境下,锰结核与药渣有机物聚团接触碰撞,大分子聚团被锰氧化物氧化为水溶性小分子后,小分子水溶性有机物经腐蚀凹孔进入结核内层,进而氧化成NH4+,H2O和CO2,锰结核由外向内逐层腐蚀;反应过程中锰氧化物晶格破坏,释放Cu,Co和Ni等有价金属元素。

Abstract: The reductive leaching of manganese from oceanic manganese nodules was investigated by using pharmaceutical residue as reducing agent. The effects of stirring speed, liquid/solid ratio, sulfuric acid concentration, dosage of pharmaceutical residue and reaction temperature on the manganese extraction were examined. The results show that the leaching efficiency of manganese peaks at 95.78% under the optimal conditions: stirring speed of 400 r/min, liquid/solid ratio of 10:1, sulfuric acid concentration of 0.94 mol/L, pharmaceutical residue dosage of 5 g, and temperature of 363 K for 300 min. At 343-368 K, the kinetic analysis is carried out based on the shrinking core model, which shows that the reductive leaching process is controlled by the chemical reaction, and the apparent activation energy is 40.74 kJ/mol. In acidic solution, with contacting and collision between oceanic manganese nodules and pharmaceutical residue, macromolecular organics is decomposed into water-soluble small molecules and finally into NH4+, H2O and CO2. Manganese nodules are reduced and dissolved by small organic molecules that contact with manganese nodules inner layer through groove by layer. Moreover, Cu, Co and Ni are released with the lattice of manganese oxides being destroyed.

相关论文

  • 暂无!

相关知识点

  • 暂无!

有色金属在线官网  |   会议  |   在线投稿  |   购买纸书  |   科技图书馆

中南大学出版社 技术支持 版权声明   电话:0731-88830515 88830516   传真:0731-88710482   Email:administrator@cnnmol.com

互联网出版许可证:(署)网出证(京)字第342号   京ICP备17050991号-6      京公网安备11010802042557号